Fiber Optic Cable

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don_resqcapt19

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Location
Illinois
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retired electrician
The cable that I had trouble with was small, 2 or 4 fiber cable, but with the kevlar and the outer jacket it was about 3/8" across.
Why did you have trouble with it? That size cable is under the fill for a single conductor in 1/2" conduit.

There is only a very small difference in the pulling tension as you increase the conduit size. The very small decrease in pulling tension is the result of a slightly smaller amount of surface area of the conductor that is in contact with the surface of the raceway as you increase the raceway size. It doesn't really make a difference that you can measure.
 

Jon456

Senior Member
Location
Colorado
Why did you have trouble with it? That size cable is under the fill for a single conductor in 1/2" conduit.

There is only a very small difference in the pulling tension as you increase the conduit size. The very small decrease in pulling tension is the result of a slightly smaller amount of surface area of the conductor that is in contact with the surface of the raceway as you increase the raceway size. It doesn't really make a difference that you can measure.
That small increase in surface area contact does play a greater role in traversing bends: as the ratio between cable diameter and conduit inside diameter increases, the "wedging" effect will increase dramatically.

Another reason a pull is easier in larger conduit (for the same single cable) is the fact that the standard bend radius of elbows increases as the conduit size increases. For example, the standard bend radius for 1/2" rigid PVC conduit is 4", whereas it's 5.75" for 1" rigid PVC conduit.
 

sparkyrick

Senior Member
Location
Appleton, Wi
Once I installed 150' of 1" smurf conduit (per AT&Tspec), then had very hard time pulling the fiber.

If you, can do 2" or larger conduit with sweeps and 24" pull box in the center.

If the conduit or the turns are too tight the fiber will break.

For some odd reason, Smurf can be a pain in the ass to pull through.
 

GoldDigger

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Location
Placerville, CA, USA
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Retired PV System Designer
For some odd reason, Smurf can be a pain in the ass to pull through.
SWAG would be a combination of not very slick kind of plastic combined with minor irregularities (including kinks) in the surface of the wire catching on the interior corrugations. That could involve as little as the pattern of a braid shield coming to the surface of the sheath.
 
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